Developer Honza Rames has a memory manager extension project which allows you to check for leaks in Android apps built with Firemonkey in Delphi 10 Seattle. The Delphi LeakCheck library works with both Android, Win32, and Win64. By default it integrates with DUnit and DUnitX. You can allocate stack traces with symbols, allocate snapshops (which are not thread safe), intercept virtual and interface calls on freed objects, plus independent object structure scanning. It includes complex leak ignoring options and there are minimal external dependencies. It is pretty simple to use in that you just add LeakCheck to your uses clause at the top and then enable ReportMemoryLeaksOnShutdown like you normally would do on Win32. It can be used as a full replacement of FastMM full debug mode but it is not as fast as possible. On Android the output from ReportMemoryLeaksOnShutdown is sent to the Android logcat functionality. Only up to Delphi XE7 is mentioned in the docs but it has been updated recently so it probably supports Delphi 10 Seattle as well. For IOS debugging try LemonJar.